Eurasian milfoil in Gulf of Mexico estuaries: does invasion of complex submerged vegetation lead to a “trophic dead end” in estuarine food webs?

10.7287/peerj.preprints.27454 ◽

2018 ◽

Author(s):

Charles W Martin ◽

John F Valentine

Keyword(s):

Gulf Of Mexico ◽

Food Web ◽

Food Webs ◽

Aquatic Vegetation ◽

Myriophyllum Spicatum ◽

Mobile Bay ◽

Dead End ◽

Faunal Communities ◽

Eurasian Milfoil

Estuaries of the northern Gulf of Mexico contain an abundance of habitat-forming submerged aquatic vegetation (SAV) that provide refuge and protection for a variety of freshwater, estuarine, and marine organisms. However, many of these estuaries now contain numerous exotic species, the ultimate impacts of which are unclear. In the Mobile-Tensaw Delta, located in the upper portion of Mobile Bay, Alabama (USA), Eurasian milfoil (Myriophyllum spicatum, hereafter referred to as Myriophyllum) is now the most dominant submerged macrophyte. Myriophyllum is a structurally-complex macrophyte with the potential to dramatically alter estuarine food webs through reduced encounter rates between predators and their prey and other mechanisms. Previously, we surveyed faunal communities using throw traps, trawls, cores, and suction sampling to compare milfoil assemblages with other native macrophytes to explore the interactive role of hydrology, diel periodicity, and macrophyte presence in influencing community structure. Here, we use this previously collected data to generate a preliminary food web analyses to determine if milfoil, due to its high complexity, creates a "trophic dead end" and limits higher trophic level production. We found the number of nodes, links, linkage density, and connectance to all be greater in milfoil than Vallisneria americana (hereafter referred to as Vallisneria), indicating that a diverse, productive, and highly connected food web exists in this invasive habitat.

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Does Invasion of Eurasian Milfoil Myriophyllum spicatum Lead to a “Trophic Dead End” and Reduced Food Web Complexity in Gulf of Mexico Estuarine Food Webs?

Frontiers in Environmental Science ◽

10.3389/fenvs.2019.00166 ◽

2019 ◽

Vol 7 ◽

Cited By ~ 1

Author(s):

Charles W. Martin ◽

John F. Valentine

Keyword(s):

Gulf Of Mexico ◽

Food Web ◽

Food Webs ◽

Myriophyllum Spicatum ◽

Dead End ◽

Eurasian Milfoil ◽

Food Web Complexity

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Coupling Modules in Space: A Landscape Theory

Food Webs (MPB-50) ◽

10.23943/princeton/9780691134178.003.0009 ◽

2011 ◽

Author(s):

Kevin S. McCann

Keyword(s):

Food Web ◽

Food Webs ◽

Large Scale ◽

Landscape Scale ◽

Food Web Structure ◽

Web Structure ◽

Web Architecture ◽

Individual Traits ◽

Bird Feeder

This chapter examines food webs at the landscape scale by focusing on the large-scale food web architecture that is deeply constrained by space. It begins with a discussion of how variability in space, time, and food web structure, coupled with the ability of organisms to rapidly respond to variation, affect the maintenance of the food web and its functions. It then explains how individual traits such as body size and foraging behavior relate to food web structure in space and time. It also considers the role of spatial constraints on food webs and how the existence of fast–slow pathways coupled by mobile adaptive predators gives rise to spatial asynchrony in the resources. The chapter concludes with a review of some empirical examples to show that some food webs display the bird feeder effect and that resource coupling of distinct habitats appears to stabilize food webs.

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Strong nutrient-plant interactions enhance the stability of ecosystems

Communications Biology ◽

10.1038/s42003-021-02737-3 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Zachariah G. Schonberger ◽

Kevin McCann ◽

Gabriel Gellner

Keyword(s):

Food Web ◽

Food Webs ◽

Plant Interactions ◽

Ecosystem Models ◽

Resource Interactions ◽

Ecosystem Theory ◽

The Stability ◽

Ecosystem Interactions ◽

Food Web Theory

AbstractModular food web theory shows how weak energetic fluxes resulting from consumptive interactions plays a major role in stabilizing food webs in space and time. Despite the reliance on energetic fluxes, food web theory surprisingly remains poorly understood within an ecosystem context that naturally focuses on material fluxes. At the same time, while ecosystem theory has employed modular nutrient-limited ecosystem models to understand how limiting nutrients alter the structure and dynamics of food webs, ecosystem theory has overlooked the role of key ecosystem interactions and their strengths (e.g., plant-nutrient; R-N) in mediating the stability of nutrient-limited ecosystems. Here, towards integrating food web theory and ecosystem theory, we first briefly review consumer-resource interactions (C-R) highlighting the relationship between the structure of C-R interactions and the stability of food web modules. We then translate this framework to nutrient-based systems, showing that the nutrient-plant interaction behaves as a coherent extension of current modular food web theory; however, in contrast to the rule that weak C-R interactions tend to be stabilizing we show that strong nutrient-plant interactions are potent stabilizers in nutrient-limited ecosystem models.

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Aggregating a Plankton Food Web: Mathematical versus Biological Approaches

Mathematics ◽

10.3390/math6120336 ◽

2018 ◽

Vol 6 (12) ◽

pp. 336 ◽

Cited By ~ 2

Author(s):

Ferenc Jordán ◽

Anett Endrédi ◽

Wei-chung Liu ◽

Domenico D’Alelio

Keyword(s):

Network Analysis ◽

Food Web ◽

Food Webs ◽

Functional Role ◽

Alternative Perspective ◽

Connection Pattern ◽

Unique Species ◽

Topological Position ◽

Biological Nature

Species are embedded in a web of intricate trophic interactions. Understanding the functional role of species in food webs is of fundamental interests. This is related to food web position, so positional similarity may provide information about functional overlap. Defining and quantifying similar trophic functioning can be addressed in different ways. We consider two approaches. One is of mathematical nature involving network analysis where unique species can be defined as those whose topological position is very different to others in the same food web. A species is unique if it has very different connection pattern compared to others. The second approach is of biological nature, based on trait-based aggregations. Unique species are not easy to aggregate with others because their traits are not in common with the ones of most others. Our goal here is to illustrate how mathematics can provide an alternative perspective on species aggregation, and how this is related to its biological counterpart. We illustrate these approaches using a toy food web and a real food web and demonstrate the sensitive relationships between those approaches. The trait-based aggregation focusing on the trait values of size (sv) can be best predicted by the mathematical aggregation algorithms.

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Food Web Fuel Differs Across Habitats and Seasons of a Tidal Freshwater Estuary

Estuaries and Coasts ◽

10.1007/s12237-020-00762-9 ◽

2020 ◽

Vol 44 (1) ◽

pp. 286-301

Author(s):

Matthew Young ◽

Emily Howe ◽

Teejay O’Rear ◽

Kathleen Berridge ◽

Peter Moyle

Keyword(s):

Food Web ◽

Food Webs ◽

San Francisco ◽

Aquatic Vegetation ◽

Environmental Variability ◽

Spatial Scales ◽

Water Channel ◽

Trophic Levels ◽

Food Sources ◽

Primary Producers

AbstractEstuarine food webs are fueled by multiple different primary producers. However, identifying the relative importance of each producer to consumers is difficult, particularly for fishes that utilize multiple food sources due to both their mobility and their generally high trophic levels. Previous studies have documented broad spatial differences in the importance of primary producers to fishes within the Upper San Francisco Estuary, California, including separation between pelagic and littoral food webs. In this study, we evaluated the importance of primary producers to adult fishes in three closely spaced subregions that represented disparate habitat types (a tidal wetland channel, a turbid backwater channel, and a deep open-water channel), each a potential outcome of local restoration projects. Using stable isotope analysis coupled with a Bayesian mixing model, we identified significant differences in primary-producer contribution to fishes and invertebrates across habitats and seasons, especially in the relative contribution of submersed aquatic vegetation and phytoplankton. Most fishes utilized multiple primary producers and showed little segregation between pelagic and littoral food webs among habitats. Availability of primary producers differs seasonally and across multiple spatial scales, helping to buffer environmental variability and thus enhancing food web resilience. Ecosystem restoration may improve with emphasis on restoring a wide variety of primary producers to support consumers.

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The interplay between fishery yield and top predator culling in a multispecies fishery context

Mathematical Medicine and Biology A Journal of the IMA ◽

10.1093/imammb/dqz017 ◽

2020 ◽

Vol 37 (3) ◽

pp. 351-363

Author(s):

Michel Iskin da S Costa ◽

Lucas Dos Anjos

Keyword(s):

Food Web ◽

Food Webs ◽

Fisheries Management ◽

Fishery Management ◽

Target Species ◽

Top Predator ◽

Predator Removal ◽

Top Predators ◽

Theoretical Population

Abstract In food webs, fishery can play the role of top predator, competing thus with other top predators for valuable food resources. In this view, it has been claimed in fisheries management that culling of top predators can be a means to improve fishery yield. To investigate this hypothesis, we use theoretical population models to assess in a multispecies context how fishery yield from target species harvest responds to top predator cull. Defying crisp summary, the four analysed food web models show that this response may be either positive or negative or both, indicating that in terms of multispecies fishery management the harvest yield may not accrue as a consequence of predator removal. In addition, this multitude of behaviours points also to the fact that the response of fishery yield to top predator cull may be difficult to assess.

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Hydrological alteration exacerbates the negative impacts of invasive Eurasian milfoil Myriophyllum spicatum by creating hypoxic conditions in a northern Gulf of Mexico estuary

Marine Ecology Progress Series ◽

10.3354/meps12517 ◽

2018 ◽

Vol 592 ◽

pp. 97-108 ◽

Cited By ~ 4

Author(s):

TC Kauffman ◽

CW Martin ◽

JF Valentine

Keyword(s):

Gulf Of Mexico ◽

Myriophyllum Spicatum ◽

Northern Gulf Of Mexico ◽

Hypoxic Conditions ◽

Hydrological Alteration ◽

Negative Impacts ◽

Eurasian Milfoil

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Landscape heterogeneity buffers biodiversity of simulated meta-food-webs under global change through rescue and drainage effects

Nature Communications ◽

10.1038/s41467-021-24877-0 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Remo Ryser ◽

Myriam R. Hirt ◽

Johanna Häussler ◽

Dominique Gravel ◽

Ulrich Brose

Keyword(s):

Habitat Fragmentation ◽

Food Web ◽

Food Webs ◽

Landscape Heterogeneity ◽

Landscape Connectivity ◽

Biodiversity Loss ◽

Mechanistic Explanation ◽

Population Densities ◽

Rescue Effect ◽

Drainage Effect

AbstractHabitat fragmentation and eutrophication have strong impacts on biodiversity. Metacommunity research demonstrated that reduction in landscape connectivity may cause biodiversity loss in fragmented landscapes. Food-web research addressed how eutrophication can cause local biodiversity declines. However, there is very limited understanding of their cumulative impacts as they could amplify or cancel each other. Our simulations of meta-food-webs show that dispersal and trophic processes interact through two complementary mechanisms. First, the ‘rescue effect’ maintains local biodiversity by rapid recolonization after a local crash in population densities. Second, the ‘drainage effect’ stabilizes biodiversity by preventing overshooting of population densities on eutrophic patches. In complex food webs on large spatial networks of habitat patches, these effects yield systematically higher biodiversity in heterogeneous than in homogeneous landscapes. Our meta-food-web approach reveals a strong interaction between habitat fragmentation and eutrophication and provides a mechanistic explanation of how landscape heterogeneity promotes biodiversity.

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